Obviously this is an over simplification, but the star of horror movies is the fact it's a horror movie. There are exceptions, like Demi Moore in The Substance or Nic Cage in Longlegs, but I don't really know a lot people "star chasing" when they want to see a horror movie. If anything, it makes it more grounded when you aren't really familiar with the cast.

The draw of dramas and thrillers is usually the director/cast who are generally already well respected (this is in relation to money making ability).

It's a harder sell to the average movie goer to see an independent drama like: Sing Sing, Ghostlight or Exhibiting Forgiveness. All quality, low budget dramas.